Game for psp.

[Pingieking]

Nobody has mentioned Jeanne D'Arc yet! That game is sweet and can easily go toe to toe against Final Fantasy Tactics: War of the Lions.
Also, Ace Combat X: Skies of Deception is by far the best game on the PSP that involved piloting a plane of any kind.
Dissidia is a choice that really can't go wrong. If you're a FF fan, you'll love it. If you're not a FF fan, you'll like the game mechanics and playstyle.
Killzone Liberation is also pretty good.

 

[Glover09]

Star Wars Battlefront Renegade Squadron, Gran Turismo, and WWE SvR 2008 are entertaining.

 

[crono738]

Dissidia and Monster Hunter Freedom Unite...that should keep you busy for a really, really long time.

 

[T5seconds]

Buy Mgs Portable Ops that game is KICK ASS...

 

[LeonLethality]

dissidia final fantasy tactics the war of the lions the star ocean remakes are pretty good loco roco theres loads of good games

 

[willard3]

I honestly had a good time with the first Legend of Heroes game. The story and characters keep you engaged, even though the dialogue is sometimes poorly translated. The combat is so-so, though.

Also the Metal Gear Acid games. They're not particularly long, but the learning curve for the first one will skullfuck you enough times that it'll add some more playtime.

 

[Kollega]

I'd recommend R&C: Size Matters/Secret Agent Clank,but i must warn you: they were not made by Insomniac,and not as cool as "main" games in the series. Still good,i guess,but...

Or Worms: Open Warfare. This one is certainly good.

 

[Vuzzmop]

Just buy wipEout: Pure/Pulse. Do it. Give a game shop some money in exchange for wipEout.